Power line communication apparatus and method for operating the same

• US 20080088418A1
• Filed: 08/14/2007
• Published: 04/17/2008
• Est. Priority Date: 08/24/2006
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Sugita, Takehiro
• Granted Patent: US 8,004,388 B2
• Time in Patent Office: Days
• US Class Current: 340/310.11
• CPC Class Codes: H04B 2203/5408 using protocols
• CPC Class Codes: H04B 2203/5416 by adding signals to the wave form of the power source
• CPC Class Codes: H04B 2203/5445 Local network
• CPC Class Codes: H04B 3/542 the information being in digital form

Abstract

Herein disclosed a power line communication apparatus which may be assigned a band window and a communication band in alternate and cyclical fashion, the band window being one to which a coexistence signal for band reservation is assignable, the communication band being one to which desired information is assignable, the power line communication apparatus may include a reception processor; a coexistence signal detector; a coexistence signal generator; a transmission processor; and a controller.

Claims

1. A power line communication apparatus which is assigned a band window and a communication band in alternate and cyclical fashion, said band window being one to which a coexistence signal for band reservation is assignable, said communication band being one to which desired information is assignable, said power line communication apparatus comprising:

a reception processor configured to receive and process a signal from a power line communication network;

a coexistence signal detector configured to detect, from the signal received by said reception processor, the presence and signal strength of said coexistence signal, and the timing of said band window which is assigned said coexistence signal;

a coexistence signal generator configured to generate a coexistence signal;

a transmission processor configured to process a signal and transmit the processed signal onto said power line communication network; and

a controller configured to effect control to establish either coexistence mode or standalone mode at power-on, said coexistence mode being one in which said band reservation is made by causing said coexistence signal generator to generate said coexistence signal and by having said transmission processor transmitting the generated coexistence signal, said standalone mode being one in which said band reservation utilizing said coexistence signal is not carried out;

said controller being further configured to effect control to make transition from one of the two modes to the other;

said establishment of one of said two modes and said transition therebetween being controlled on the basis of said coexistence signal being detected by said coexistence signal detector, on the basis of the signal strength of said coexistence signal if the presence of the signal is detected, or on the basis of both the signal strength of said coexistence signal and the timing of said band window which is assigned said coexistence signal.

2. The power line communication apparatus according to claim 1, wherein said controller establishes said standalone mode if said coexistence signal is not detected, or if every coexistence signal detected has a signal strength of less than a predetermined level P3;

and

wherein said controller establishes said coexistence mode if at least one coexistence signal is detected at power-on and if the signal strength of at least one of the detected coexistence signals is at least on said level P.

3. The power line communication apparatus according to claim 2, wherein, if all coexistence signals detected at power-on are found to have signal strength levels less than said level P3, then said controller controls said coexistence signal generator and said transmission processor in such a manner as to transmit a coexistence signal at the timing of said band window of each detected coexistence signal.

4. The power line communication apparatus according to claim 2, wherein, if one band window is detected which is assigned a coexistence signal with a signal strength of at least said level P3 upon establishment of said coexistence mode, then said controller controls said coexistence signal generator and said transmission processor in such a manner as to transmit a coexistence signal through a band window at the same timing as that of the detected band window;

and

wherein, if a plurality of band windows are detected each of which is assigned a coexistence signal with a signal strength of at least said level P3 upon establishment of said coexistence mode, then said controller controls said coexistence signal generator and said transmission processor in such a manner as to standardize the timings of the detected plurality of band windows and to transmit a coexistence signal through a band window at the standardized timing.

5. The power line communication apparatus according to claim 2, wherein, with said standalone mode in effect, if said coexistence signal is not detected or if the signal strengths of all detected coexistence signals are less than a predetermined level P2, then said controller maintains said standalone mode;

wherein, with said standalone mode in effect, if a plurality of band windows are detected each of which is assigned a coexistence signal with a signal strength of at least said level P2, then said controller controls said coexistence signal generator and said transmission processor in such a manner as to standardize the timings of the detected plurality of band windows, transmit a coexistence signal through a band window at the standardized timing, and effect transition to said coexistence mode; and

wherein, with said standalone mode in effect, if one band window is detected which is assigned a coexistence signal with a signal strength of at least said level P2, then said controller effects transition to said coexistence mode without standardizing the timing of the detected band window.

6. The power line communication apparatus according to claim 5, wherein, upon transition to said coexistence mode without standardization of the timing of said band window, if the timing of the detected band window with the assigned coexistence signal is different from the timing of the band window assigned to this apparatus, then said controller controls said coexistence signal generator and said transmission processor in such a manner as to transmit a coexistence signal through a band window at a timing different from that of this apparatus before effecting transition to said coexistence mode.

7. The power line communication apparatus according to claim 5, wherein, with said coexistence mode in effect, if at least one of the detected coexistence signals has a signal strength of at least a predetermined level P1 which is less than said level P2, then said controller may maintain said coexistence mode;

and

wherein, with said coexistence mode in effect, if no coexistence signal is detected or if every detected coexistence signal has a signal strength of less than said level P1, then said controller effects transition to said standalone mode.

8. The power line communication apparatus according to claim 5, wherein, with said coexistence mode in effect, if at least one of the detected coexistence signals has a signal strength of at least a predetermined level P1 which is less than said level P2, then said controller may maintain said coexistence mode;

and

wherein, with said coexistence mode in effect, if no coexistence signal is detected, or if every detected coexistence signal has a signal strength of less than said level P1 and if the timing of every detected coexistence signal is different from the timing of the band window assigned to this apparatus, then said controller controls said coexistence signal generator and said transmission processor in such a manner as to transmit a coexistence signal through a band window at a timing different from that of this apparatus before effecting transition to said standalone mode.

9. The power line communication apparatus according to claim 2, wherein, if every coexistence signal detected at power-on has a signal strength of less than said level P3, then said controller effects transition to said standalone mode without transmitting a coexistence signal.

10. The power line communication apparatus according to claim 5, wherein, with said coexistence mode in effect, if at least one of the detected coexistence signals has a signal strength of at least a predetermined level P1 which is less than said level P2, then said controller may maintain said coexistence mode;

and

wherein, with said coexistence mode in effect, if no coexistence signal is detected, or if every detected coexistence signal has a signal strength of less than said level P1, then said controller controls said coexistence signal generator and said transmission processor in such a manner as to stop transmitting a coexistence signal before effecting transition to said standalone mode.

11. The power line communication apparatus according to claim 10, wherein said controller using random numbers determines at least either the time at which to stop sending said coexistence signal or the time ranging from the stopping of coexistence signal transmission to resumption of the signal transmission, and controls said coexistence signal generator and said transmission processor in such a manner as to stop transmitting said coexistence signal and to resume the transmission.

12. A method for operating a power line communication apparatus which is assigned a band window and a communication band in alternate and cyclical fashion, said band window being one to which a coexistence signal for band reservation is assignable, said communication band being one to which desired information is assignable, said method comprising the steps of:

detecting, from a received signal, the presence and signal strength of said coexistence signal, and the timing of said band window which is assigned said coexistence signal;

checking to determine, upon detection;

of said coexistence signal, whether a plurality of coexistence signals are detected from a plurality of band windows occurring at staggered intervals; and

effecting control in such a manner as to establish either coexistence mode or standalone mode at power-on, said coexistence mode being one in which said band reservation is made by generating said coexistence signal and by transmitting the generated coexistence signal, said standalone mode being one in which said band reservation utilizing said coexistence signal is not carried out;

said control effecting step further effecting control to make transition from one of the two modes to the other;

said establishment of one of said two modes and said transition therebetween being controlled on the basis of said coexistence signal being detected, on the basis of the signal strength of said coexistence signal if the presence of the signal is detected, or on the basis of both the signal strength of said coexistence signal and the timing of said band window which is assigned said coexistence signal.